<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category  Zend
 * @package   Zend_Config
 * @copyright Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license   http://framework.zend.com/license/new-bsd     New BSD License
 * @version   $Id: Xml.php 17267 2009-07-29 02:13:18Z yoshida@zend.co.jp $
 */

/**
 * @see Zend_Config
 */
require_once 'Zend/Config.php';

/**
 * XML Adapter for Zend_Config
 *
 * @category  Zend
 * @package   Zend_Config
 * @copyright Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license   http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Config_Xml extends Zend_Config
{
	/**
	 * XML namespace for ZF-related tags and attributes
	 */
	const XML_NAMESPACE = 'http://framework.zend.com/xml/zend-config-xml/1.0/';

	/**
	 * Wether to skip extends or not
	 *
	 * @var boolean
	 */
	protected $_skipExtends = false;

	/**
	 * Loads the section $section from the config file (or string $xml for
	 * access facilitated by nested object properties.
	 *
	 * Sections are defined in the XML as children of the root element.
	 *
	 * In order to extend another section, a section defines the "extends"
	 * attribute having a value of the section name from which the extending
	 * section inherits values.
	 *
	 * Note that the keys in $section will override any keys of the same
	 * name in the sections that have been included via "extends".
	 *
	 * @param  string  $xml     XML file or string to process
	 * @param  mixed   $section Section to process
	 * @param  boolean $options Whether modifiacations are allowed at runtime
	 * @throws Zend_Config_Exception When xml is not set or cannot be loaded
	 * @throws Zend_Config_Exception When section $sectionName cannot be found in $xml
	 */
	public function __construct($xml, $section = null, $options = false)
	{
		if (empty($xml)) {
			require_once 'Zend/Config/Exception.php';
			throw new Zend_Config_Exception('Filename is not set');
		}

		$allowModifications = false;
		if (is_bool($options)) {
			$allowModifications = $options;
		} elseif (is_array($options)) {
			if (isset($options['allowModifications'])) {
				$allowModifications = (bool) $options['allowModifications'];
			}
			if (isset($options['skipExtends'])) {
				$this->_skipExtends = (bool) $options['skipExtends'];
			}
		}

		set_error_handler(array($this, '_loadFileErrorHandler')); // Warnings and errors are suppressed
		if (strstr($xml, '<?xml')) {
			$config = simplexml_load_string($xml);
		} else {
			$config = simplexml_load_file($xml);
		}

		restore_error_handler();
		// Check if there was a error while loading file
		if ($this->_loadFileErrorStr !== null) {
			require_once 'Zend/Config/Exception.php';
			throw new Zend_Config_Exception($this->_loadFileErrorStr);
		}

		if ($section === null) {
			$dataArray = array();
			foreach ($config as $sectionName => $sectionData) {
				$dataArray[$sectionName] = $this->_processExtends($config, $sectionName);
			}

			parent::__construct($dataArray, $allowModifications);
		} else if (is_array($section)) {
			$dataArray = array();
			foreach ($section as $sectionName) {
				if (!isset($config->$sectionName)) {
					require_once 'Zend/Config/Exception.php';
					throw new Zend_Config_Exception("Section '$sectionName' cannot be found in $xml");
				}

				$dataArray = array_merge($this->_processExtends($config, $sectionName), $dataArray);
			}

			parent::__construct($dataArray, $allowModifications);
		} else {
			if (!isset($config->$section)) {
				require_once 'Zend/Config/Exception.php';
				throw new Zend_Config_Exception("Section '$section' cannot be found in $xml");
			}

			$dataArray = $this->_processExtends($config, $section);
			if (!is_array($dataArray)) {
				// Section in the XML file contains just one top level string
				$dataArray = array($section => $dataArray);
			}

			parent::__construct($dataArray, $allowModifications);
		}

		$this->_loadedSection = $section;
	}

	/**
	 * Helper function to process each element in the section and handle
	 * the "extends" inheritance attribute.
	 *
	 * @param  SimpleXMLElement $element XML Element to process
	 * @param  string           $section Section to process
	 * @param  array            $config  Configuration which was parsed yet
	 * @throws Zend_Config_Exception When $section cannot be found
	 * @return array
	 */
	protected function _processExtends(SimpleXMLElement $element, $section, array $config = array())
	{
		if (!isset($element->$section)) {
			require_once 'Zend/Config/Exception.php';
			throw new Zend_Config_Exception("Section '$section' cannot be found");
		}

		$thisSection  = $element->$section;
		$nsAttributes = $thisSection->attributes(self::XML_NAMESPACE);

		if (isset($thisSection['extends']) || isset($nsAttributes['extends'])) {
			$extendedSection = (string) (isset($nsAttributes['extends']) ? $nsAttributes['extends'] : $thisSection['extends']);
			$this->_assertValidExtend($section, $extendedSection);

			if (!$this->_skipExtends) {
				$config = $this->_processExtends($element, $extendedSection, $config);
			}
		}

		$config = $this->_arrayMergeRecursive($config, $this->_toArray($thisSection));

		return $config;
	}

	/**
	 * Returns a string or an associative and possibly multidimensional array from
	 * a SimpleXMLElement.
	 *
	 * @param  SimpleXMLElement $xmlObject Convert a SimpleXMLElement into an array
	 * @return array|string
	 */
	protected function _toArray(SimpleXMLElement $xmlObject)
	{
		$config       = array();
		$nsAttributes = $xmlObject->attributes(self::XML_NAMESPACE);

		// Search for parent node values
		if (count($xmlObject->attributes()) > 0) {
			foreach ($xmlObject->attributes() as $key => $value) {
				if ($key === 'extends') {
					continue;
				}

				$value = (string) $value;

				if (array_key_exists($key, $config)) {
					if (!is_array($config[$key])) {
						$config[$key] = array($config[$key]);
					}

					$config[$key][] = $value;
				} else {
					$config[$key] = $value;
				}
			}
		}

		// Search for local 'const' nodes and replace them
		if (count($xmlObject->children(self::XML_NAMESPACE)) > 0) {
			if (count($xmlObject->children()) > 0) {
				require_once 'Zend/Config/Exception.php';
				throw new Zend_Config_Exception("A node with a 'const' childnode may not have any other children");
			}

			$dom                 = dom_import_simplexml($xmlObject);
			$namespaceChildNodes = array();

			// We have to store them in an array, as replacing nodes will
			// confuse the DOMNodeList later
			foreach ($dom->childNodes as $node) {
				if ($node instanceof DOMElement && $node->namespaceURI === self::XML_NAMESPACE) {
					$namespaceChildNodes[] = $node;
				}
			}

			foreach ($namespaceChildNodes as $node) {
				switch ($node->localName) {
					case 'const':
						if (!$node->hasAttributeNS(self::XML_NAMESPACE, 'name')) {
							require_once 'Zend/Config/Exception.php';
							throw new Zend_Config_Exception("Misssing 'name' attribute in 'const' node");
						}

						$constantName = $node->getAttributeNS(self::XML_NAMESPACE, 'name');

						if (!defined($constantName)) {
							require_once 'Zend/Config/Exception.php';
							throw new Zend_Config_Exception("Constant with name '$constantName' was not defined");
						}

						$constantValue = constant($constantName);

						$dom->replaceChild($dom->ownerDocument->createTextNode($constantValue), $node);
						break;

					default:
						require_once 'Zend/Config/Exception.php';
						throw new Zend_Config_Exception("Unknown node with name '$node->localName' found");
				}
			}

			return (string) simplexml_import_dom($dom);
		}

		// Search for children
		if (count($xmlObject->children()) > 0) {
			foreach ($xmlObject->children() as $key => $value) {
				if (count($value->children()) > 0 || count($value->children(self::XML_NAMESPACE)) > 0) {
					$value = $this->_toArray($value);
				} else if (count($value->attributes()) > 0) {
					$attributes = $value->attributes();
					if (isset($attributes['value'])) {
						$value = (string) $attributes['value'];
					} else {
						$value = $this->_toArray($value);
					}
				} else {
					$value = (string) $value;
				}

				if (array_key_exists($key, $config)) {
					if (!is_array($config[$key]) || !array_key_exists(0, $config[$key])) {
						$config[$key] = array($config[$key]);
					}

					$config[$key][] = $value;
				} else {
					$config[$key] = $value;
				}
			}
		} else if (!isset($xmlObject['extends']) && !isset($nsAttributes['extends']) && (count($config) === 0)) {
			// Object has no children nor attributes and doesn't use the extends
			// attribute: it's a string
			$config = (string) $xmlObject;
		}

		return $config;
	}

	/**
	 * Merge two arrays recursively, overwriting keys of the same name
	 * in $firstArray with the value in $secondArray.
	 *
	 * @param  mixed $firstArray  First array
	 * @param  mixed $secondArray Second array to merge into first array
	 * @return array
	 */
	protected function _arrayMergeRecursive($firstArray, $secondArray)
	{
		if (is_array($firstArray) && is_array($secondArray)) {
			foreach ($secondArray as $key => $value) {
				if (isset($firstArray[$key])) {
					$firstArray[$key] = $this->_arrayMergeRecursive($firstArray[$key], $value);
				} else {
					if($key === 0) {
						$firstArray= array(0=>$this->_arrayMergeRecursive($firstArray, $value));
					} else {
						$firstArray[$key] = $value;
					}
				}
			}
		} else {
			$firstArray = $secondArray;
		}

		return $firstArray;
	}
}
